Clinical Question

Are epidural corticosteroid injections safe and more effective than other injections for the treatment of lumbosacral radicular pain?

Evidence-Based Answer

Epidural corticosteroid injections for the treatment of lumbosacral radicular pain may offer modest short-term (two weeks to three months) benefit compared with placebo injection for radicular leg pain (mean difference [MD] = −4.93; 95% CI, −8.77 to −1.09 on a scale of 0 to 100) and disability (MD = −4.18; 95% CI, −6.04 to −2.17 on a scale of 0 to 100). After three months, there does not appear to be any added benefit with the use of corticosteroid.¹ (Strength of Recommendation: B, based on inconsistent or limited-quality patient-oriented evidence.) Minor adverse effects from corticosteroid injection are no more common than with placebo injection, based on very low-quality data.

Practice Pointers

Lumbosacral radicular pain is radiating pain that results from injury or irritation of nerve roots in the lower back. Lumbosacral radicular pain is most often caused by disc herniation with nerve root compression. Most patients with this condition improve over time, but the degree of pain and disability is variable and leads some patients to seek invasive intervention. Epidural corticosteroid injections can be administered in an outpatient setting. This review sought to determine if epidural corticosteroid injection is more effective than placebo injection for the treatment of lumbosacral pain and disability.

This Cochrane review included 25 randomized trials and 2,470 patients¹; it updates a previous 2012 review. Six additional studies were added to this review, but the overall conclusions were largely unchanged from 2012. The review considered only trials that included a placebo injection as the control arm of the study. Results of individual studies were grouped by timing of response measured and thus characterized as immediate (less than two weeks), short term (two weeks to three months), intermediate term (three to 12 months), and long term (more than 12 months). Pain assessment varied among studies but was converted to a 100-point scale for the purpose of comparison. Disability assessment also varied from study to study, but the authors converted these assessments to a 100-point scale as well. It is important to note that injection of steroid was compared with injection of saline or local anesthetic rather than watchful waiting, physical therapy, or surgical intervention.

Comparison between studies is complicated by data gathering at different times after injection and by the studies reporting a single pain level (pain intensity) vs. the difference in pain after treatment (pain relief). Anatomic location of pain vs. overall pain end points further complicates comparison analysis.

Epidural corticosteroid injections were slightly more effective than placebo in reducing leg pain at short-term follow-up (MD = −4.93; 95% CI, −8.77 to −1.09 on a scale of 0 to 100). Epidural corticosteroid injections were also slightly more effective than placebo in reducing disability at short-term follow-up (MD = −4.18; 95% CI, −6.04 to −2.17 on a scale of 0 to 100).

Epidural corticosteroid injections do not appear to be more effective than placebo at intermediate- or long-term follow-up for reducing overall pain, back pain in general, pain relief, or risk of disability. The caveat is that both types of injection can result in some immediate and long-term pain relief that is not well characterized in this review. The trend over time is for diminished benefit regardless of the injection used.

The U.S. Food and Drug Administration has warned that injection of corticosteroids into the epidural space of the spine may result in rare but serious adverse effects, including loss of vision, stroke, paralysis, and death.² It has been suggested that these rare complications are the result of particulate steroids; no adverse outcomes have been reported with epidural corticosteroid injections when nonparticulate steroids were used. A separate study, not included in this review, demonstrated no difference in effectiveness between particulate and nonparticulate steroids, but it remains unclear if the risk of adverse effects is different.³ For select patients, the amount of pain and disability relief may justify epidural injection, with or without steroids, after a shared decision-making process.^4,5 The additional short-term pain relief gained by adding steroids to the injection may not be clinically significant.

The practice recommendations in this activity are available at http://www.cochrane.org/CD013577.

The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or reflecting the views of the Department of Defense or the Uniformed Services University of the Health Sciences.